1. Field of the Invention
The present invention relates to a wire-gathering device for positioning wires such as a plurality of electrical wires at the center of a rotating drum when winding the electrical wires with an adhesive tape. The present invention also relates to an apparatus and a method of winding the adhesive tape around the wires utilizing the wire-gathering device.
2. Description of the Related Art
FIG. 6 shows a conventional tape-winding apparatus having a conventional electrical wire-gathering device (JP, H07-215599, A and especially FIG. 9).
The tape-winding apparatus 65 is a handy type and includes a rotating drum 67 having a notch 66 to accept a plurality of electrical wires (not shown), a positioning plate 68 as an electrical wire-gathering device to slidably adjust an inner width of the notch 67, a swing plate 69 to support the positioning plate 68 with a roller, and a tape reel 71 disposed on an axle 70 of the swing plate 69 and wound with an adhesive tape.
The positioning plate 68 includes an L-shaped electrical wire support surface 68a, which forms a rectangular shaped wire support face with a support surface 66a of the notch 66. The electrical wires are inserted into the notch 66 and the positioning plate 68 is moved to abut an outer periphery of the electrical wires. The rotating drum 67 is then rotated with a motor to wind the outer periphery of the electrical wires with the adhesive tape.
JP, H07-215599, A also discloses that a tape-winding apparatus includes a pair of positioning plates (not shown) symmetrically positioned each having a circular support surface, the positioning plates being symmetrically slid to support the electrical wires at the center of a rotating drum.
FIGS. 7A and 7B show a conventional tape-winding apparatus (JP, H09-183413, A) having a conventional electrical wire-gathering device.
The tape-winding apparatus 50 is a stationary type and includes a rotating drum 57 having a notch 61 to accept a plurality of electrical wires in a bundle, a pair of brushes 62 as an electrical gathering device disposed in the notch 61, a motor to drive the rotating drum 57 via a gear 58, rollers 52, 55 and a guide plate 56 to supply an adhesive tape made of a synthetic resin to a side of an opening 61a of the notch 61, a gear 53 to drive the roller 52, and a movable blade 59 and a stationary blade 60 to cut the adhesive tape 54 short of the rotating drum 57.
The electrical wires 63 and the adhesive tape 54 are both inserted between the brushes 62 and the adhesive tape 54 is wound around the electrical wires 63 in a direction indicated by an arrow to gather the electrical wires 63.
FIGS. 8A and 8B are a conventional handy type tape-winding apparatus including an electrical wire-gathering device.
The electrical wire-gathering device includes a rotating drum 73 having a notch 74, in which a rectangular slider 75 is supported back-and-forth with a coil spring 76.
At beginning of winding an adhesive tape 78, a plurality of electrical wires 77 are loosely positioned approximately at the center of the rotating drum 73 with a slider 75 as shown in FIG. 8A. An end portion 78a of the adhesive tape 78 bonds a return portion 78b. As shown in FIG. 8B, the rotating drum 73 rotates about one revolution and the adhesive tape 78 is thus wound around the electrical wires 77 as a primary winding. Further rotation of the rotating drum 73 in the same direction enables a plurality of windings of the adhesive tape 78 around the electrical wires 77 as a secondary winding (not shown).
The conventional electrical wire-gathering devices utilizing the positioning plate 68 or the like (not shown) have a disadvantage to move to and abut the positioning plate 68 the outer surface of the electrical wires for gathering, resulting in a tolerance work and complicated structure.
The conventional electrical wire-gathering device of FIG. 7B encounters problems for outer diameters of the electrical wires 63. When the diameter of the bundled electrical wires is much smaller than the gap between the pair of brushes, the electrical wires 63 swing between the brushes 62, and when the diameter thereof is much larger than the gap between the pair of brushes, the brushes 62 get crushed.
The conventional electrical wire-gathering device of FIGS. 8A-8C has a disadvantage such that the electrical wires 77 wound in the primary winding move along a receiving surface 75a in a lateral direction of the notch 74 when the rotating drum 73 rotates approximately by one revolution as shown in FIG. 8C. A further rotation of the rotating drum 73 swings the electrical wires 77, resulting in losing its own looks at the secondary winding.
These problems encounter winding of a corrugated tube (protection tube of harness) covering the electrical wires 63 and other wires besides the electrical wires 63.